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ALMAS A. .KNOWLTON, OF Si. ALBANS, VERMONT.

Letters Patent lll'o. 75,027, dated llfm'ch 3, 18681 digiv Srlgniizlrnfcrrch lx1-inflitte gisting @what mit limiting nrt at 'un smid.V

TO ALL WHOM IT MAY CONCERN: p A

Be it known that I, ALMAS A; KNOWLTON, ol Slt/(Albans, in the countj,1 of Franklin, and Stateof Vermont,

i have invented a. new and improved Mould for Artificial Teeth and I do hcre\hy declare .that the following is a.

full, clear, and exact description thereof', which will enableothers skilled' in the art to nlalteandusethe same, reference being had to the accompanying drawings, fdrmingpurt of' this specification.

vFigure 1 isa perspective view of my improved mould. f l

Figure 2 is a detail sectional view of the same, taken Vthrough the line yy, iig. l. p

.Figure 3 is a. detail sectional view ci' the same, taken through the line xm, iig; 1.

Similar letters of reference indicatecorresponding par-ts.-

Myinvention has for its object to furnish an improved mould for forming 'artificial teeth, which shall be simple in construction, eiective, and convenient in operation, andnvhioh will obviate the diiculties heretofore attending the moulding of articial teeth; and it consists inzdividng the back part of the mould into two parts, iu the combination of screws with 'the baelrpartof the' mouldgin the formation of holes for the.'platina pins, und in the combina-tion of dowel-pins and screws with thepaijts, ofV the mould," the whole being' constructed andv' arranged as hereinafte'more fully described. I.

A is the front part or half of the mould, which contains the'forms of the labial' and bruccul sides of the teeth. B and C are the p arts or pieces which togethcrmake up the back pnrt'or half of the mould, and which contain the forms of the lingual sides of the teeth. The piefccs'B endC are secured in place upon the front part A, when necessary, by the-screws d, which pass through ,the said parts B and C,- a'nd screw into the said part A. e are dowel-pins to hold the pieces B and C in proper position upon the part A. fare pins whiclfpass` through the pieces B andi-C to hold them together when the mould is opened. z are screws which go through the part C into the inside of the mould to form the helical holes in the teeth.

The holes for the platina pins are formed in the bevelled edge of the piece-O, as shown at the'point K, in iig. 2, in such positions that 'the said platina, pins when in the teeth may be at an angle of about twenty degrees or thirty degrees with the plane of the position of said teeth when in the mouth, so that the said-pins may be set at such an angle as will increasethe strength ofthe teeth.- The screws h should be inserted in thev piece C at an angle of about twenty degrceswith the line of division J between the pieces B and C, and shouldl enter the teeth about as far from the grinding-surface of said teeth as the platina pins are usually set. The screws h should havonV-Shaped threads formed upon them, making about twenty-live turns to an inch, should'be about; one-tenth ofan inch in diameter for molars, and about one-twelfth of an inch for bicuspids, and should penctrate the teeth about halt' way through. It is most convenient in practice to Vhave two moulds for cach set of teeth, one for the'molars and bicuspids, and the other for the canines and incisors. The division between the pieces or parts B and C should be about one-sixteenth of anpinch from the grinding-surface of the molars, or about equally distant between the end of the tooth and the point where the screw z enters said tooth. The division betweenv the parts B and C iu the case of incisors should be about one-sixteenth of an inch from the holes for the platina pins, and o u the side towards the points of said teeth. The hole in thepart C, for the reception of the screws L, is bored through the part C from the inside of said piece; it is then reamed out or couutersunk from the, outside to within about an eighth of an inch from the inside, said countersink being of such a size as to receive the hea-d of said screw. The remainder of said hole then has a screw-thread cut in it. The screws d go entirely through the mould, and are about one-sixth of an inch in diameter. The holes for the screws d are bored through'the back pieces B- and C, and about hali` through the part A. A smaller drill is then used, and a. screw-thread is then` cut in the smaller part ot`- the holes. 'lhe pinsfare made of wire, about .one-eighth of an inch in diameter, pass horizontally through the pieces B and G near their ends, should closely fit the holes in which they areplaced, and should `have one of. their ends bent to form a-handle for convenience in handling them. v

In using the mould, the'back piece B is placed upon the front. piece A, and Vsecured in place by the screw d. The material for the point or crownof the tooth is put into the mould, then the yellow for the base, and lastly, the body. The piece C is then put on, pressed down, and secured in place without disturbing the material for the crown and base of the teeth. The screws L are then turnedl forward until they penetra-te the teeth to a. sutHcient depth, after which the pinsjl are put into their` places to keepthe pieces B ond C in positionvwhen the mould is opened.

'In taking teeth from the mould, the front part A is firstv removed, theny the screws h are turned'hacli out of the teeth, the pinsfare then removed and the parts B and C separated: The 'teeth may then he removed with the fingers or hy gently rapping the mould.

In melting patterns for a. mould, take patterns of such teeth as the mould is te contain, and arrange them upon softened wax with the crowns all inthe same direction, with the lingual sides up, and so that astraight lline will cross each tooth at the point Where the line of separation between the pieces B sind C is to be, which is neer the point where the platinaipins are usually set, and upon the side of said points towards the points or crowns of said teeth. The indcntations in the crowns of the molars und bicuspids should hecoverod over with wax, so that they may be removed from. the back part of the pattern. The front and back patterns are then mode inthe Sinne manner as for common moulds. The bnc-lc piece or pattern is then removed, (leavin,r the teeth in the front putterm) and the side in which thev crowns of the teeth :tre is planed-down te the line Jof division between the parts B and C, thus forming the part C of the pattern. The part C is then returned to its place upon the front piece, the wax removed from the crowns of the molars and bicuspids, the crowns of the teeth and tho surface of the plaster' are vnrnished to prevent adhesion, :tud the part planed away is again filled with pla-ster, thus forming -the piece B. It is advisable to form V-shape-l grooves or notches in the front pu-rt A, and have them filled from the buck parts B and G, as seen at z', fig. l, as it Will assist in zuiljustinarfy the pieces ct'ter they have been separat-ed, and will also facilitate the finishing ot the mould. 1he patterns should hev so shaped that they can be drawn from the` moulding-sand when the withdrawing-tool is inserted in the sides marked L in iig. 3.

I claim as new, and desire to secure hyLetters Patentl. Forming the hack partei' the mould-in two pieces B and C, the division-line being located substantially as herein shown and described, and for the purpose set forth.

2. The combination of the screws 7L with the back part C of the mould, substantially as herein shown and described, andfor the purposes set forth.

3. Forming the holes for the platina pins in plain incisore and canines in the bevclled edge of the'part C, and :it an angle of twenty degrees or thirty degrees with the plane ot' the position of snid teeth when in the mouth, substantiallfzts hereinsho'ivn and described, und for the purpose set forth.

4. The combination of the screws Z with the parts 13,10, and A, of the mould, substantially as herein shown and described, and lfor the purpose set forth.

5. The combination of the pinsfwith the parts B and C of the mould, substantially as herein shown and described, and for the purpose set forth.

ALMAS A.' KNOWLTON.

\Vitnesses:

RAWsoN BRAINERD, J. H. LEONARD. 

